CALCULATION OF CHARACTERISTIC X-RAYS IN DIAGNOSTIC-X-RAY SPECTRUM

We examined the experimental data of Fewell et al. [Handbook of Comput ed Tomography X-Ray Spectra (HHS Publication, Rockville, 1981) No. 81- 8162], which exhibited the variation of the characteristic radiation y ield with the beam angle, but did not confirm any model proposed by pr evious workers to explain its variation. We developed a new method of calculating the intensity of the characteristic radiation for the X-ra y tube used in medical diagnosis. Our method was based on the photoele ctric interactions of the bremsstrahlung photons with the target mater ial, where the bremsstrahlung spectra used were calculated taking into account the electron energy distributions in a target material descri bed in our previous paper. Our method did not include any adjustment p arameters to fit with experimental data. Our calculated results are in good agreement with the experimental results of Fewell et al. In part icular, the dependence of the intensity of the characteristic radiatio n on the beam angle, calculated using our method, agreed with the expe riment results of Fewell et al., while the methods proposed by previou s workers led to the reverse dependence.